Permanent magnet telemetric system



Patented Feb. 18, 1947 zs ssss PERMANENT MAGNET TELEMETRIC SYSTEM Paul F. Bechber ger, Tenafly, and Wladimir A. Reichel, Hackensack, N. J assignors to Bendix Aviation Corporation, Bendix, N. J a corporation of Delaware Application March 12, 1942, Serial No. 434,428

4 Claims. (Cl. 172-239) The present invention relates to self-synchronous systems and more particularly to systems with the use of which motion of any kind at one point may be transmitted to and reproduced at another and remote point.

Systems of this general nature are known in the art as illustrated, for example, by the patent to W. A. Reichel, No. 2,269,602, issued January 13,

1942, and assigned to the assignee of the present.

current systems necessitated the use of brushes,

commutators, or sliding contacts. The use of these elements obviously hindered correct remote transmission of motion from one point to another point because considerable torque is needed to overcome the friction created with the use of brushes, commutators or sliding contacts, These systems are especially undesirable where the movement of a sensitive instrument, such as a magnetic or gyroscopic compass, is to be reproduced at a, remote point because only a limited amount of torque is available at the instrument.

An object of the present invention, therefore,

is to provide a, novel direct current self-synchronous system which overcomes the foregoing disadvantages.

Another object of the present invention is to provide a novel brushless direct current self-synchronous system.

A further object of the invention is to provide novel means for reproducing motion at a remote point.

Another object of the invention is to provide a novel transmitter having no brushes, commutators or sliding contacts for use in a direct current self-synchronous system.

Still another object of the invention is to provide a novel direct current remote control system with the use of which an object or device at one point may be controlled by an object or device at another and a remote point.

A further object is to provide a novel direct current remote control system having a novel transmitter which dispenses with the use of brushes, commutators or sliding contacts.

Another object of the invention is to provide a novel, brushless, direct current transmitter having several interconnectedv conductor ele-- ments which are formed of a substance such as bismuth, for example, so that the electrical resistance of the conductors varies in the presence of a magnetic field.

The foregoing and other objects and advantages of the inventionwill appear more fully hereinafter from a, consideration of the detailed description which follows, taken together with the accompanying drawing wherein one embodiment of the invention is illustrated by way of example. ever, that the drawing is for purpose of illustration and description only and is not intended as a definition of the limits of the invention.

In the drawing wherein like reference characters refer to like parts, throughout the several views;

Figure 1 is a diagrammatic illustration of one form of the novel apparatus embodying the present invention and shows a transmitter and a receiver with their magnetic and electrical circuits and connections;

Figure 2 is a detail view of the novel transmitter of Figure 1 showing the arrangement of the novel stator resistors with the rotor magnet; and

Figure 3 is a fragmentary schematic view illustrating an-arrangement of biasing means for the transmitter of Figure 2.

The present invention contemplates the provision of a. novel direct current repeater system having a brushless transmitter connected electrically with a remote receiver whereby motion of any kind detected at the transmitter is reproduced at the receiver. The problem heretofore encountered with the use of known direct current repeater systems was that the brushes, commutators or sliding contacts thereof demanded constant attention and frequent repair or replacement. It is known that the electrical resistance of bismuth to the flow of current is varied in the presence of a strong magnetic field. This latter property of bismuth is utilized to provide a novel direct currentrepeating system having a brushless and contactless transmitter device thereby overcoming the foregoing disadvantages associated with the use of known systems.

Referring now to the drawing for a more detailed description of the present invention and particularly to Figure 1 thereoL-a novel repeater It is to be expressly understood, howsystem is shown comprising a transmitter In which is electrically connected to a remote receiver |l.

. Transmitter It comprises a stator having three resistors 2, l3 and H which are connected together at a common mid-point with a suitable source of direct current l5 by way of a conductor l6.

Stator resistors |2, l3 and M are constructed so as to be substantially alike and under normal conditions have equal currents flowing therethrough from source l5. Furthermore, in accordance with the present invention, these resistors are formed of a substance such as bismuth, for example, whose electrical resistancev varies in. the presence of a magnetic field.

Receiver comprises a stator having three windings I8 and I9 which, through a common mid-point, likewise, connect by way of conductor l6 with the other side of source 5. The free ends of windings l1, I8 and |9 connect by way of leads 20, 2| and 22 with the free ends of resistors |2, |3 and I4.

The transmitter stator resistors |2, l3 and I4 I have magnetically associated therewith a rotor 23 comprising a rotatable magnetic disc, one half of which defines the North pole designated at N and the other half of which defines the South pole designated at S. Angular movement of transmitter rotor 23 relative to its stator causes an equal and corresponding angular movement, in a manner to presently appear, on the part of a receiver rotor 24, which, like rotor 23, comprises a rotatable magnetic disc, one half of which defines the North pcle designated at N and the other half of which defines the South pole designated at S.

-Receiver rotor 24 is mechanically coupled by means of a shaft 25 with a suitable indicator 28 superimposed for movement over a calibrateddial 21. Only one repeater II has been shown in the present instance but it is to be specifically understood that any number of such receivers may be used at different points, all of which would be electrically connected to connecting leads 20, 2| and 22 in the same manner that receiver H is connected thereto.

Transmitter l0, shown diagrammatically in Figure 1, may be constructed somewhat in the manner as illustrated in Figure 2, which comprises winding resistors |2, l3 and I4 about an annular supporting stator member 28, with a like end of each resistor connected to source 5 by way of the common conductor l6 and with the free ends thereof to the receiver H of Figure 1 by way of leads 20, 2| and 22.

For purposes of illustration, magnetic transmitter rotor 23 is shown in Figure 2 as influenced and controlled by a magnetic compass 29 which may be of any known type and comprises a compass bowl 30 having mounted therein, in suitable bearings, a spindle 3| carrying a compass needle or element 32. Rotor 23 is arranged concen trically with the annular supporting member 28 and its resistors and, furthermore, is rotatably mounted for movement with compass needle 32 upon a spindle 33 which may be connected'to or formed integrally with spindle 3|.

Magnetic compass 29, furthermore, may be provided with a'conventional deviation compensator 34 of any known type at the top thereof.

Bismuth resistors, though sensitive to a change in the intensity of a magnetic field, are not selective as to the direction of the effective magnetic field. Stated in another manner, if the nular stator member 28 by means such as a bracket 36, with its N pole directly above the central axis of rotor 23. Magnet 35 acts to provide a biased field emanating from rotor 23 because the N pole of magnet 35 acts additively with the N pole of rotor 23 and differentially with the rotor S pole. Thus, stator resistors |2, I3 and H are made sensitive to both the direction and intensity of the rotor field.

When the craft or moving object, upon which the present novel system is mounted, deviates from a northerly or prescribed course, the compass bowl 30 moves angularly therewith but the compass needle 32 remains in its original position so that relative movement results between the compass bowl and the needle, the amount of such relative movement being the amount of the angular departure of the craft or moving object from its northerly or prescribed course.

The stator of transmitter I0, like compass bowl 30, is fixed to the craft or moving object so that it, too, moves angularly with the craft or object producing thereby relative movement between the annular supporting member 28 with its stator resistors |2, |3 and I4 and the magnetic rotor 23 because the latter is coupled with the compass needle spindle 3| by way of spindle 33.

The amount of relative movement between stator resistors |2, I3 and I4 and the magnetic rotor 23 determines which of the resistors is to be influenced by the magnetic field being provided by magnetic rotor 23. Since resistors |2, l3 and J4 are all the same, the current flow through each one of them from source |5 would be the same and, obviously, should the value of the resistances not be the same the currents flowing through each of the resistances would no longer be the same.

If the amount of the angular craft movement is such as to bring resistor |2 in front of the N pole of poled rotor 23, resistor |2, being formed of bismuth, responds to the strong magnetic field of the rotor so that its electrical resistance is varied whereby the amount of current flowing through resistor l2 becomes different from the current flowing in resistors l3 and H. The variation in the relationship of the flowing currents is communicated to the receiver windings l1, l8

, and I9, and, obviously, the current flowing in winding I! will be difierent in amount from the The change in the currents flowing in receiver windings I1, l8 and I9 causes a change in the intensity of the magnetic fields created about each of the windings so that the effective resultant of the composite magnetic fields is varied and exerts a torque upon receiver rotor 24 until the latter moves angularly into agreement with the position of transmitter rotor 23. Movement of rotor 24 urges indicator 26 over scale 21 to indicate the amount of angular craft movement.

During a greater angular change of craft heading from a prescribed course, bismuth resistors i3 or 4 may be brought directly in front of the N pole of transmitter rotor 23 and similarly the value of their resistances would change in the presence of the strong field which change would be communicated to the receiverwindings l1, l8

and is producing a rotating magnetic field at the receiver which coacts with the poled receiver rotor 24 to urge the latter a further angular amount corresponding to the amount of angular c an e of craft heading.

It ill now be apparent to those skilled in the art that a novel and highly desirable direct current self-synchronous system has been provided having a novel brushless and contactless transmitter whose resistors are formed of a substance such as bismuth, the electrical resistances of which vary in the presence of a strong magnetic field. Furthermore, the system is such that all direct connections with the actuating element or instrument are dispensed with thereby overcoming the former disadvantages where the contacts or brushes engaging the transmitter resistors were connected directly to and moved' by the sensitive instrumenti As stated before, the transmitter rotor 23 has been shown as connected by means of spindle 33 to compass needle spindle 3| for actuation thereby. It is to be understood, however, that the compass needle itself may act as the transmitter rotor thereby replacting the use of the transmitter rotor 23 of Figure 2, in the manner shown and described in the copending application, Serial No. 410,343, filed September 10, 1941, and assigned to the assignee of the present invention.

Although only one embodiment oi the invention has been illustrated and described in detail, various changes and modifications in the form and relative arrangement of the parts, which will now appear to those skilled in the art, may be made without departing from the scope of the invention. Reference is, therefore, to be had to the appended claims for a definition of the limits of the invention.

What is claimed is:

l. A transmitter device comprising a stator having a closed substantially annular core member, means spaced about said core member for conducting current therethrough formed 01 bismuth, a rotatable magnetic rotor mounted for movement relative to said stator whose magnetic field influences the electrical resistance of said conducting means, and means providing a second magnetic field for coaction with the magnetic field of said rotor.

2. In apparatus of the class described a substantially annular stator member, current conducting means on said member formed of a material whose electrical resistance varies in the presence of a relatively movable magnetic field, a magnetic rotor mounted for movement relative to said conducting means, and means providing a second'magnetic field for coaction with the magnetic field of said rotor.

3. In combination, a transmitter comprising a closed substantially annular core having resistive coil means spaced thereon, said coil means being formed or bismuth and having a single connection and a multi-circuit connection, amagnetic rotor in influencing relationship with said coil means for varying the electrical resistance of said coil means and thus the current flow therethrough, means providing a second magnetic field for coaction with the magnetic field of said rotor, a receiver comprising a stator having windings provided with a single connection and a multi-circuit connection, the multi-circuit connection of said coil means being connected to the multi-circuit connection of said receiver windings in corresponding circuit relation, a source of direct current connected to both of said single connections, and a rotatable magnetic rotor associated with said windings for actuation by the reaction between its own magnetic field and the field produced by the windings upon rotation of the magnetic transmitter rotor.

4. In combination, a transmitter comprising a closed substantially annular core having resistive coil means spaced thereon, said coil means being formed of a material whose electrical resistance varies in the presence of a magnetic field and having a single connection and a multi-circuit' connection, a magnetic rotor in influencing relationship with said coil means for varying the electrical resistance of said coil means and thus the current flow therethrough, means providing a second magnetic field for coaction with the magnetic field of said rotor, a receiver comprising a stator having windings provided with a single connection and a multi-circuit connection, the multi-circuit connection of said coil means being connected to the multi-circuit connection of said receiver windings in corresponding circuit relation, a source of direct current connected to both 01' said single connections, and a rotatable magnetic rotor associated with said windings for actuationby the reaction between its own magnetic field and the field produced by the windings upon rotation of the magnetic transmitter rotor.

PAUL -F. BECHBERGER. WLADIMIR A. REICHEL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 543,843 Biggar Aug. 6, 1895 2,013,106 Nagel Sept. 3, 1935 2,184,347 Jewell Dec, 26, 1939 2,226,847 Clark Dec. 31, 1940 2,365,430 Naul Dec. 19, 1944 FOREIGN PATENTS Number Country 'Date 409,318 German Feb. 4, 1925 502,144 German July 9, 1930 OTHER. REFERENCES Fownes Manual of Chemistry, by Henry Watts, published by Henry C. Lea, Philadelphia, 1878, pages 112-113. 

